Rila Monastery Nature Park Management Plan - part - usaid

February 2004 Appendix 8
Geological
era
Paleozoic
Period Main Geological Manifestation throughout the World Main Geological Manifestation in Rila
Ordovician
Beginning 490 – end
435 million years
Silurian
Beginning 435 – end
400 million years
Devonian
Beginning 400 – end
345 million years
Occurrence of the first vertebrates, corals etc. and of the
first terrestrial vegetation (psylophytes)
Subsidence of the northern continents and marine
transgression over them. At the end of the period –
tectonic folding phase (Appalachian, Grampian, Alpine-
Himalayan belt). Vast continental glaciations over
northern Africa.
Occurrence of shelled fishes and terrestrial insects.
Transgression over the western part of the Russian
platform. The Siberian and part of the Canadian platforms
are under water. The Chinese platform and Gondwana
land are dry.
Folding of the entire Grampian belt and partial folding of
the Ural-Tienshan and Mongol-Ohotsk belts. Formation
of new mountain systems – caledonides. Formation of
two paleocontinents in the north – Laurasia and
Angaraland. Raising of the continents and marine
regression at the end of the period.
Occurrence of goniatites, terrestrial (stegocephalians),
ferns etc. During the middle Devonian – another raising
and regression of the northern continents and
transgression of the sea on parts of them. Another raising
and regression at the end of the period. Weak folding
(Bretonian orogeny) in the moving belts, marking the
beginning of a new Tectonic cycle. Vegetation covers
significant portions of the earth’s surface.
Rila Monastery Nature Park
Management Plan (Draft) – Appendices
2004 - 2013
The area is subject to severe tectonic
movements.
Transgression of the Ordovician sea water in
the early Silurian owing to slow dry-land
subsidence. Beginning of sediments forming
graptoloid schists and this subsidence of the
Earth’s crust has formed the so-called
Protothetic geosyncline.
Continued development and lengthening of
the protothetic geosyncline. The Rhodopides
is subject to folding in the Caledonian
folding orogeny.
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